Volume shrinking,Minimization energy,Annealing

Hi every body

How I can subject a polymer amorphous cell to volume shrinkage under NVT.

I want reduce the cell volume by shrinking all sides of the rectangular periodic box by equal amounts and after that minimize for energy, then annealing cycle. This process of volume reduction and temperature annealing should carry out until the real density achieve.

Would you help me please?

Best regard